The goal of this research is to determine the physiological substrates for the mammalian peroxisomal enzymes: D-amino acid oxidase, D-aspartate oxidase, and L-alpha-hydroxy acid oxidase. Chemical considerations and preliminary indications suggest that substrates for these enzymes may be formed by the reaction of glyoxylate with various other metabolites. Therefore, the specific aims of the research are to explore this possibility, and to thoroughly characterize any such reactions which appear like they could be occurring physiologically. Various aspects of the research will include: surveying a large number of metabolites as possible participants with glyoxylate and oxygen in a reaction catalyzed by the above enzymes; determining the basic kinetics of any new reactions found; and isolating, identifying and synthesizing the products of the reactions.